Overcasting foot attachment for sewing machines



May 19, 1970 D. L. WENER 3,512,490

OVERCASTING EQOT ATTACHMENT FOR SEWING MACHINES Filed April 29, 1968LVVEA/"IUR.

30 34 az 54:40 Z. fl iA/fe W%,%,% a; M 265045 United States Patent3,512,490 OVERCASTING FOOT ATTACHMENT FOR SEWING MACHINES David L.Wener, 324 N. Palm Canyon Drive, Palm Springs, Calif. 92262 Filed Apr.29, 1968, Ser. No. 725,010 Int. Cl. D05b 29/00 US. Cl. 112-235 8 ClaimsABSTRACT OF THE DISCLOSURE An overedge or overcasting presser footattachable to a household zigzag sewing machine. Disposed between thepresser foot forward edge and the needle opening is an edge guide wall.Projecting laterally from the base of the guide wall is a flatpositioning blade that slides beneath the material margin to slightlyraise the edge and position it against the guide wall to keep the edgein perfect alignment during stitching. A tongue extends rearwardlythrough the needle opening to assist in making the stitches sufficientlytaut to prevent the edge from ravelling and curling.

BACKGROUND OF THE INVENTION The present invention relates to a presserfoot attachment for a household zigzag sewing machine, and morespecifically to an overedge presser foot having an edge guide formaintaining continuous accurate alignment between the presser foot andthe raw material edge to achieve a neat finished edge.

An established technique for binding the untidy raw edges of materialconsists of using a conventional household zigzag sewing machine inconjunction with a presser foot that assists the sewing machine inbinding the edge with overedge or overcast stitching. The presser footrests upon and slides over the material edge while holding the materialsteady by pressing it against the machine table or platform as overedgestitching proceeds. In practice, it is difficult to keep conventionaloveredge presser feet in continuous alignment with the raw materialed-ge and therefore the completed stitched edge is often crooked,disorderly and unsightly. Ordinarily the sewing machine operator seeksto stitch a smooth edge by visually aligning the material edge with astraight guide wall or line of the presser foot (e.g., US. Pat.2,950,696 to Miller).

Another prior art approach aimed at keeping the material edge andpresser foot aligned during overedge stitching is characterized byattaching a vertically aligned edge guide to an outside section of thepresser foot. This type of edge guide must extend below the plane of theflat presser foot under-surface and therefore the guide is eitherseverely restricted by the thickness of the material or must bevertically adjusted to accommodate materials of varying thicknesses(e.g., US. Pat. 736,199 to Borton and US. Pat. 1,944,515 to Karle).

Another drawback of conventional presser feet is that they causecompleted stitched edges to appear unfinished due to the fact thatravelling is not effectively prevented and the stitching is appliedunder excessive'tension so that the edge either curls or ridges. Inaccordance with one approach (e.g., the Miller patent previouslymentioned) some of these disadavntages are sought to be overcome byattaching to the presser foot a tongue projecting rearwardly into theneedle opening that accommodates the zigzag stitching action of theneedle. Stitching is drawn over the tongue by the back and forth actionof the needle and the tongue serves to sufficiently relax the tension inthe stitching so that the eventually stitched edge is free of curling.

SUMMARY OF THE INVENTION Briefly described, the present inventioncomprehends a presser foot attachable to a household zigzag sewingmachine for assisting the machine in binding material edges withoveredge or overcast stitching. The presser foot includes a plate formedwith a flat undersurface portion which slides over the marginal edge ofthe material to be stitched to hold the material steady duringstitching. Formed through a central region of the plate is a typicalneedle opening for accommodating the zigzag stitching action of theneedle. Disposed between the plate forward edge and the needle openingis a straight edge guide wall that bears against the raw material edgeduring stitching to keep the raw edge and presser foot in smooth mutualalignment. Arranged adjacent the guide wall is positioning means thatfunctions to position the material edge in constant engagement with theguide wall. Preferably the positioning means is characterized by a flatpositioning blade projecting laterally from the lower edge of the guidewall which provides a smooth angular transition between the verticalguide wall and the horizontal blade to prevent snagging the materialedge. The positioning blade slides beneath the material margin andslightly raises the material edge into position against the guide wall.In accordance with one construction of the present invention, the guidewall is formed by an inner wall portion of an arm aligned in laterallyspaced relationship from a second arm. A for ward portion of the secondarm curves upwardly over the blade to define therewith a shallowentrance passageway through which the margin of the raw material iscontinuously fed to a location beneath the needle open ing. In order torelax tension in the stitches and therefore prevent curling or ridgingof the completed stitched edge, the plate may include a tongue extendingrearwardly into the needle opening where it terminates in a free end.Stitching loops freely slip over the free end of the tongue while beingfed rearwardly to neatly bind the material edge. The tongue may beextended beneath an undercut section of the plate to define therewith ashallow guide slot which assists in guiding the stitching loops to theireventual stitching positions on the material edge. In order to furtherassist the presser foot in maintaining the marginal edge steady duringstitching, the lower surfaces of the positioning blade and tongue arearranged in substantially coplanar relationship with the fiatundersurface portion of the plate. A connection element pivotallyconnected to a rearward section of the plate may be used for connectingthe presser foot to the sewing machine.

The unique aspects and advantages of the present invention serve toeliminate or substantially minimize the previously mentioneddisadvantages and defects of conventional presser feet. The edge guidewall and the positioning blade which continuously slides beneath thematerial mar-gin during stitching, coact to assure that the presser footis maintained in constant alignment with the material edge so that asmooth regular edge can be achieved. The tongue simultaneously operatesto relax the otherwise excessive tension in the stitching loops so thatwhen the stitches are eventually woven into and around the edge, theedge is free of ravelling, ridging and curling.

BRIEF DESCRIPTION OF THE DRAWINGS The unique aspects and advantages ofthe present invention will be fully understood when the followingdetailed description is studied in conjunction with the drawings inwhich:

FIG. 1 is a perspective view of the overedge presser foot, showing thezigzag needle raised above the needle opening when the foot is connectedto the sewing machine;

FIG. 2 is a bottom view of the presser foot, showing the material edgerunning over the positioning blade and under the tongue which extendsbeneath an undercut portion of the plate;

FIG. 3 is a front view of the presser foot, showing how one arm curvesupwardly to slide smoothly over the material margin;

FIG. 4 is a side elevational view;

FIG 5 is a partially sectional side view, showing the material marginrunning over the positioning blade and under the tongue;

FIG. 6 is a sectional view taken along line 6-6 of FIG. 5, showing howthe plate undercut section and tongue are vertically spaced to define ashallow guide slot for the marterial margin.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings,FIG. 1 shows a presser foot 10 for binding the edge of a material withoveredge stitching often referred to as overcast or overseam stitching.Presser foot 10 includes a main body or plate 11 which has a pair oflaterally spaced bosses or lugs 12 and 13 thereon formed with coalignedopenings for receiving a pivot pin that pivotally connects the presserfoot 10 to a connector element or shank 14. The top of shank 14 isformed with a socket for receiving a presser bar or slide bar 15 that isconnected to a household zigzag sewing machine (not shown). Slide bar 15and shank 14 may be securely coupled together by tightening aconventional set screw 16. A conventional needle bar 17 carries a needle18 that is movable in a typical zigzag path to draw stitching thread 19through the material whose edge is being stitched. Extending between theleading or forward edge 20 of plate 11 and a needle opening 21 thataccommodates the zigzag movement of needle 18 is a slot 22 which dividesthe forward region of plate 11 into a pair of laterally spaced forwardlyextending arms 23 and 24.

An inner wall portion 25 of arm 23 constitutes a substantially verticaledge guide 'wall that is flat and straight with respect to theanticipated direction of the path of movement of the material under thepresser foot 10. Guide wall 25 is shaped and located so as to makecontinuous flush sliding engagement with the edge of the material thatis being overedge stitched. By keeping edge guide wall 25 in engagementwith the raw material edge during stitching, mutual alignment betweenthe material edge and presser foot 10 is assured so that otherwisecrooked and unsightly completed edges are avoided. In addition, edgeguide wall 25 serves to lay down and precompress randomly orientedfibers of the raw edge so that their tendency to ravel is decreased. Inorder to smoothly place the material edge against edge guide wall 25,positioning means is provided characterized by a generally horizontalpositioning blade 26 that is preferably integrally connected to thelower edge of guide wall 25 and extends inwardly toward opposing arm 24.The positioning blade 26 provides a smooth angular transition betweenthe vertical guide wall 25 and a horizontal surface defined by the uppersurface of the positioning blade 26 to prevent snagging of the materialedge.

As shown in FIGS. 1, 2 and 3 positioning blade 26 extends beneath theforward section of arm 24 to define therewith a shallow entrancepassageway 27 (as shown in FIG. 4) through which the material margin iscontinuously fed during stitching. The forward portion of arm 24 iscurved forwardly and upwardly to provide mal plane of the material whichoverlies a table or platform 29. As distinguished from lifting the rawedge into engagement with an edge guide wall such as guide wall 25,conventional edge guides are mounted on an external presser foot sideand lowered beneath the flat undersurface of the presser foot where theyconstitute obstructions that can delay the stitching operation and, aspreviously mentioned, either must be adjusted to accommodate varyingmaterial thicknesses or are severely restricted to materials within alimited range of thicknesses. Guide wall 25 and blade 26 do not requireadjustments and no portion of either of them depends below the fiatundersurface portion 30 of plate 11. The undersurface portion of blade26 is preferably flat and arranged in substantially coplanarrelationship with plate undersurface 30 to assist undersurface 30 inpressing material 28 against platform 29.

Referring to FIG. 2 and FIG. 5, plate 11 is integrally formed with aflat rearwardly projecting tongue 31 that symetrically bisects needlsopening 21 and terminates in a free end 32. End 32 is disposed beneath arecessed or undercut section 33 formed in fiat undersurface portion 30.Under cut section 33 and tongue end 32 are vertically spaced from oneanother to define a shallow guide slot 34, best shown in FIG. 6, throughwhich stitching loops pass. The zigzag action of needle 18 steppingalternately between the divided sections of needle opening 21 drawsstitching thread 19 laterally across the preferably rounded top surfaceof tongue 31. Stitching loops slip reanvardly over tongue 31 and throughguide slot 34 to eventually stitch the material edge in the desiredmanner. Tongue 31 is positioned and shaped so that when the stitches arewoven into the material edge they will be sufiiciently taut toeffectively bind the edge fibers and prevent them from ravelling and yetnot taut enough to promote ridging or curling of the edge. Theundersurface of tongue 31 is flat and arranged in substantially coplanarrelationship with the undersurface of plate 11 and blade 26 to assistthem in holding material 28 steady during stitching.

It will thus be clearly seen that during overedge stitching thepositioning blade 26 and edge guide wall 25 coact to maintain continuousmutual alignment between the material edge and presser foot 10 as tongue31 releases stitching loops under the optimum tautness so that thefinished stitched edge is continuously smooth and free of ravelling,ridging, and curling.

What is claimed is:

1. An over edge presser foot capable of being attached to a zig-Zagsewing machine comprising:

a plate having forward and rearward edges and a flat undersurfaceportion, the plate being adapted to overlie the marginal edge of thematerial to be stitched;

means forming a needle opening through the plate for accommodating thezig-zag stitching motion of a needle;

spaced arms defined by a slot disposed between the plate forward edgeand the needle opening;

a straight guide wall constituted by an inner wall portion of one ofsaid arms;

a positioning blade connected to the lower edge of the guide wall toprovide a substantially smooth angular transition between the guide walland the blade, the blade being arranged to slide beneath the materialmargin to position the material edge against the guide wall to maintaincontinuous alignment between the material edge and presser foot duringover-edge stitching; and

a tongue connected to the plate extending rearwardly into the needleopening, the tongue terminating in a free end positioned so thatstitching loops can freely slip therefrom to neatly bind the materialedge.

2. The structure according to claim 1 wherein:

the undersurface of a plate section located immediately rearward of theneedle opening is undercut and 5 the tongue extends beneath the undercutsection to define therewith a shallow guide slot through which thestitching loops pass; and

the undersurface of the tongue is in substantially coplanar relationshipwith the plate flat undersurface portion.

3. The structure according to claim 1 further comprising:

a connection element pivotally connected to the plate,

the connection element being dimensioned for connection to the sewingmachine.

4. The structure according to claim 8 wherein:

the forward portion of the other arm curves upwardly over the blade todefine therewith a shallow entrance passageway through which thematerial margin is continuously fed to a location beneath the needleopening.

5. An overedge presser foot capable of being attached to a zig-Zagsewing machine comprising:

a plate having forward and rearward edges and a flat undersurfaceportion, the plate being adapated to overlie the marginal edge of thematerial to be stitched;

means forming a needle opening through the plate for accommodating thezig-zag stitching motion of a needle;

spaced arms defined by a slot disposed between the plate forward edgeand the needle opening;

a straight guide wall constituted by an inner wall portion of one ofsaid arms;

positioning means arranged adjacent the guide wall for positioning thematerial edge in engagement with the guide wall which then operates tomaintain continuous alignment between the material edge and presser footduring overedge stitching; and

a tongue connected to the plate extending rearwardly into the needleopening, the tongue terminating in a free end positioned so thatstitching loops can freely slip therefrom to neatly bind the materialedge.

6. The structure according to claim 5, wherein:

the undersurface of a plate section located immediately rearward of theneedle opening is undercut and the tongue extends beneath the undercutsection to define therewith a shallow guide slot through which thestitching loops pass; and

the undersurface of the tongue is in substantially coplanar relationshipwith the plate flat undersurface portion.

7. The structure according to claim 1, wherein:

the guide wall is fiat and generally perpendicular to the plate flatundersurface portion.

8. The structure according to claim 5, wherein:

the guide wall is flat and generally perpendicular to the plateundersurface portion.

References Cited UNITED STATES PATENTS 2,478,073 8/1949 Antonelli 1121512,699,743 1/1955 Hill 112151 X 2,950,696 8/1960 Miller 112-235 3,304,8962/1967 Laidig 112-235 3,370,559 2/1968 Longcore 112-235 PATRICK D.LAWSON, Primary Examiner mg UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3 ,5l2,490 Dated May 19 1970 Inventor(s) DavidWener It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:

Column 5, line 12, after "claim",

Delete "8" and substitute therefor l-.

SIGNEB'ANU- SEALED ISEAL) A teat:

mm M Fletcher! If. Anew; offimmm 1:. m.

Oomissioner of Patents

